Sin
by Exceeds Expectations
Summary: This is how we witness sin; from the outside looking in. /Lily says she loves James, but it's Sirius she takes to bed. And they all know it. For Kelly.


**A/N: **For my darling Kelly, who enables me to enable her to enable me in all things stalkerish and creepy. I love you, dearest. I hope you like this!

And thanks to the fabulous Sammie for betaing!

* * *

**i. james**

* * *

She always smells like Lily when he leaves.

She always smells like _him_ when he comes back.

* * *

**ii. lily**

* * *

Merlin, she's fucked it all up now.

She's got Sirius lips tracing promises into the hollow of her throat and James' surname hiding from his tongue. Where it should trail limply after the litany of _Lily Lily Lily_, there is only silence and heavy breaths and heartbeats too quick to count.

(And she doesn't even feel guilty about it. Not really.)

* * *

**iii. sirius**

* * *

Sirius knows that this is wrong. She _tells_ him it's wrong, she tells him to _stop_ – but she never means it. He tells her maybe Prongs doesn't mind – maybe he doesn't even _know_.

"He would've stopped us by now, Lils," he says, pressing his lips to her temple. "He wouldn't let me have my way with his wife if he actually knew."

"He loves me," she says, and he hopes that she won't cry this time. She does. She always does. "He told me he'd do anything to see me happy."

Sirius kisses away the tears on her cheeks and pulls her close to his chest.

"Telling a girl you'll do _anything _to see her _happy_ doesn't include letting her shag other blokes in her free time," he says. "That's just something a bloke says to get a girl into bed. Trust me. I should know."

He grins lewdly, running his hands down her back and slipping his thumbs under the elastic of her knickers.

"You're awful, you know that?" She laughs, and he thinks he's gotten away with it this time.

"Bloody terrible," he says, kissing her quickly.

And they do not bring it up again.

* * *

**iv. lily**

* * *

The first time burns her conscience like Sirius' hands burns her skin.

The taste of wine and firewhisky is heavy on their breaths, mixed with the scent of lost sobriety and soon-to-be regrets, and Lily smiles with false confidence and lust in her bones.

"You're fucking beautiful," Sirius says.

"You're fucking delusional," Lily whispers, but she still lets him kiss her.

She still lets him push her back, further, until the scratchy carpet tickles her bare skin and Sirius' teeth are dragging across her shoulder and his hands are hot on her sides, and his hips painfully slow in their movements, his thrusts staggeringly brilliant and surprisingly tender, and he says, "Don't pretend you don't need me."

But he says it so quietly that Lily doesn't think he's surprised when she doesn't respond.

She just wraps her arms around his neck, arches her back and says, "_Harder_."

Because there are nights for softness and tenderness and romance. And there are nights for desperation and roughness and _treat me like I deserve to be treated,_teeth in skin and nails scraped down backs.

(She tells herself that there are nights for both of them. Nights for James. Nights for Sirius.

Both. No matter how wrong that is.)

* * *

**v. james**

* * *

He finds Sirius' watch on the bedside locker when he gets back.

"What is this doing here?" he asks her.

"That? Oh, Sirius asked me to fix it for him. Said the second hand had stopped. Only had a chance to look at it last night when I finally got Harry to sleep."

But she keeps those green eyes on the floor, keeps her voice a little too level.

And James just pretends he still doesn't know. It's easier this way.

* * *

**vi. lily**

* * *

She is a tangle of blankets, caught in her own bed with Sirius' kiss on her lips, and she thinks it's all only for comfort, only that.

It is just lust, just _sex_, just anything to hide from the reality of those cold, lonely nights, from James' constant missions for the Order, from the mistrust lurking in Sirius' smiles, from Remus' weary sighs and tired eyes, from Peter' twitchy, mistrustful movements, from Harry's cries, from _everything._

Everything.

But this is not everything; this is comfort. Only comfort.

* * *

**vii. sirius**

* * *

"Something's wrong, Pads," he says, and his gaze his heavy Sirius' face.

"'Course something's wrong, you twat," Sirius says. "There's a madman after you! What did Dumbledore say?"

"That we should go into hiding. Choose a secret keeper. Keep out of the way."

Sirius looks up slowly, face impassive and still.

"Who're you gonna ask?"

James cocks his head to the side. "You, Pads. I – we _both_ – think it would be best. We need you."

_We._ James' eyes are too open right there, too honest and raw and hollow and _understanding _and _oh, fuck, he knows_ but _shit, he doesn't care _and _what do I say?_

"That might be a bit too obvious though. I'm your best mate," he says, feeling the guilt crawl up his throat with it sharp fingers and fall from his mouth in the shape of unuttered apologies.

"Best mate," James says quietly. "Yeah."

"What about Remus?" Sirius swallows and his throat is dry and sore. James' eyes are still too much.

He says nothing.

"Peter?"

"I'll talk to Lily in the morning." He drops his gaze, _finally_, and Sirius sighs.

But he doesn't expect the fist that comes flying his way, connecting with his cheekbone.

"Best mate," James pants. "My fucking _best mate._"

"I'm sorry," Sirius chokes, but the door slams and James is gone. Sirius' jaw burns and he can taste blood.

(It is almost as sweet as Lily, and just as bitter.)

* * *

**viii. lily**

* * *

He watches her move.

She can feel it on her skin, the tingle of his gaze burning into the back of her neck, and she knows that he's trying to push the accusations from his tongue, trying to blame her, or Sirius, or anyone but himself.

"I love you," he says.

"I love you, too," she whispers, but she doesn't look at him. She can't.

"If he makes you happy..." James says, voice low and scratchy. "I just want you to be happy."

Lily's eyes fill with tears, her breath stuck in her throat.

"You make me happy, James," she says. "You do."

"But I'm not enough for you, am I?"

"That's not it, James, I just – "

"I love you, Lily," he says, and the desperation in his voice burns right through her chest. "But I don't think you realise how much it hurts to see you love –"

"It's – it's not like that," she blurts. "It's nothing like that, James, it's just – just –"

"Just sex? He's just a quick fuck for when I'm away? Is that it?" he demands, his voice growing louder, more confident, and she still cannot look at him.

"James – I – no –," she stutters, turning on her heel, and his hazel eyes are so full of pain that it knocks the air from her lungs. "James. _James_."

"It doesn't matter anymore," he croaks. "Nothing does."

And he Apparates away.

* * *

**ix. sirius**

* * *

She is warm in his arms, all curves and softened edges, all broken down barriers and tears on his bare chest, and he whispers so many _I'm sorry_s that the words stop making sense.

"I love you," he says.

She says nothing.

(But it's okay, he thinks, because she's Lily and she doesn't need to say it to mean it.)

"I love you," he says again, and he hopes to Merlin she's listening.

* * *

**x. james**

* * *

He wonders if she knows how wrong it all is. Because she's Lily and she's his and she's perfect – except for when she isn't.

_This is how we witness sin; from the outside looking in_.

The worst part is that he knows he can't hate her for it.

The worst part is that he knows she's in _his_ arms, and he still wants to hold her close and kiss her and tell her how much she means to him.

The worst part is that he would die for her.

(And the very worst part is that he does.)


End file.
